The only answer I can think of for your question is that

> Languages have many differences.  If all verbs matched up perfectly, in meaning and usage, such as transitive/intransitive, reflexive/not reflexive, then we would lose the beautiful variability and richness of the world's languages.  How boring that would be! 

However, I thought you might like to know that there's another way of expressing the same concept, that *is* reflexive (pronominal):

**iniciarse**

> Las clases se inician el 27 de agosto.